Lighting fixture



.JOC- f D Search Room Feb. 27, 1940.

l.. SCHEPMOES.

LIGHTING FIXTURE Filed May 1, 193'.' 2 Sheets-Sheet 1 INVENTOR l/vosLerSCHEPMOES [Qing/0MM ,M/

ATTORNE S Feb. 27, 1940.

L. SCHEPMOES LIGHTING FIXTURE Filed May 1, 1937 2 Sheets-Sheet 2INVENTOR UNDSLEY Sc//gPMoE BY @4). ai@ @wf WJ ATToRNE'l Patented Feb.27, 1940 UNITED STATES PATENT ori-ice LIGHTING FIXTURE Application-May1, 1937, serial No. 140,126

2 Claims.

This invention relates to a lighting fixture and more particularly to alighting fixture and lens for illumination of a railroad car or thelike.

In accordance with the seating arrangement of 5 modern railroad cars,busses and similar vehicles, it is often desirable to provideA lightingfixtures which not only harmonize with the interior decoration of thevehicles but which effectively provide localized illumination. Many suchvehicles are provided with aligned pairs of seats over which a baggagerack extends and which are more eectively illuminated by light sourceswhich illuminate generally the entire interior of the vehicle. Suchillumination is often too weak to l5 provide sufficient reading lightbut is, nevertheless, productive of glare and light streaks which causeeye strain. When such xtures are increased in illuminating power, theresulting glare is still more bothersome. Still other fixtures whichattempt to provide localized illuminaiton,

for each pair of seats do so indifferently because of improper location,poorlens structure, and

numerous other reasons. These fixtures also very often cause anatmosphere of gloominess in the upper portions of the car andaccordingly detract from rather than enhance the interior decorationthereof.

It is accordingly among the objects of this invention to provide alighting fixture for a railroad car or similar vehicle which isreasonably inexpensive, sturdy, durable under conditions of "rigoroususe,.which effectively illuminates the' reading plane in the car withoutcreating a condition of glare and finally which enhances the generalappearance of the car interior.

The invention accordingly consists, in the features of construction,combinations of elements, and arrangements of parts, all .as will beillustratively described herein, and the scope of the 40 application ofwhich will be indicated in the following claims.

In the accompanying drawings in which are shown two of the variouspossible embodiments of my invention,

Figure 1 is a longitudinal sectional elevation of my light fixture;

Figure 2 is a bottom plan view of the fixture;

Figure 3 is a sectional elevation taken along the line 3--3 of Figure 2;

Figure 4 is a diagrammatic view showing .the

distribution of light from the lens in my fixture;

and l Figure 5 is a sectional elevation of a modified form of myfixture.

Similar reference characters refer to similar (CL 24o-7.35)

parts throughout the several views of the drawings.

Referring rst to Figure 1, my light fixture comprises generally ahousing indicated at I9 which mounts an electric bulb socket II holdinga bulb I2, casing II) having removably mounted therein a lens generallyindicated at I3.

Still referring to Figure l, casing I0 is preferably an integraldie-casting or stamping of suitable material such as aluminum and com loprises a dome-like reflector. portion I4, 'the inside I5 of which issuitably coated or finished to reiiect light rays from bulb or lightsource. I2. An opening I6 is provided in refiector I4 through which theopen end of socket II extends in bulb- 15 receiving position. Casing I0also includes substantially vertical side portions Il (Figure 3) 1 whichjoin refiector I4 with a flange portion I8 (see also Figure 1) whichforms a mounting surface for the casing. I also provide an integral 20socket mounting plate I9 provided with a sub-. stantially U-shapedopening 20 by which socket II may be mounted in any suitable manner.

A pair of bosses 2| (Figure 1) are provided along one transverse end ofcasing I0 and on 25 these bosses I secure a bracket 22 'as by screws 23for a. purpose hereinafter described. On the other transverse end ofcasing III I provide a similar pair of bosses 2l (Figures 1 and 3) onwhich are secured similar brackets 25 as by screws 26 30 (Figure 1).

As is more clearly shown in Figure 2, casing iiange I3 has a. suitablenumber of screws 21 extending therethrough which may be threaded into 4aportion 28 (Figure 1) of the baggage rack I (for example) or the ceilingof a railroad car or the like to mount the casing therein.

Brackets 22 and 25 are provided respectively with horizontal portions22a and 25a having suit-y able hbles formed therein through which extendn respectively lens supporting hooks 29 and 30. As all of these hooksare substantially the same, only one will be described. 'I'hus hook 29(Figure 1) has a. collar 3| suitably secured thereto and between thiscollar and casing flange I8 a spring 32 is coiled about hook 29. Spring32 is an expansion spring and accordingly thrusts against collar 3l toforce hook 29 upwardly to cause lens supporting arm 29a thereof to pullagainst'the bottom of one edge of lens I3 thus l, f holding the lensagainst casing flange I8 in proper operative position. Similarly lenshooks 30 are provided with springs 33 which force hook arms 30a againstthe bottom of the opposite edge of lens I2 to hold it in position.

side portions 34 resting against casing ange I8. The outer surfaces ofside and bottom portions 34 and 35 preferably are corrugated, i. e. theyhave parallel ridges 36 formed thereon (Figure 2) which are suitablytreated so as to have a diffusing surface rather than a clear surface.

It may now be seen that lens I3 may be readily installed or detachedfrom casing I .bythe manipulation of hooks 29 and 30 as these hooks maybe pulled downwardly against the action of springs 32 and 33 and thencetwisted to swing hook arms 29a and 30a away from the bottom of the lens.l y l Positioned substantially, centrally of lens bottom portion 35(Figure 2) is a twin-'condenser lens generally indicated at 31. As isbetter shown in Figure 1, twin condenser lens 31 comprises two lensportions 38 and 39 (Figure 1) lying in the same general plane. As eachof these lens portions is substantially similar to the other, only onelwill be described hereinafter. Lens portion 38 accordingly has an upperconvexsurface 40 (see also Figure 3) which extends from a point 4I whereit joins the bottom 35 of lens I3 to a point 42 where it joins the upperconvex surface 43 of lens portion 39, point 42 being equidistant fromthe lcenters o.f lenses 38 andv 39 andrpreferably being aligned with thecenter of source I2. With reference, to Figure 3, the bottom surface oflens portion 38 is formed in a'series of concentric prisms 44, 45 and46, the lower surfaces of each of which are preferably concentricallyconvex. The central portion 41 of the bottom surface of lens 38 is alsopreferably convex. Lens portion 39 is similarly provided with concentricprisms 48, 49 and 50 having convex surfaces and with a convex lowersurface I. Thus condenser lens 31 comprises in general`a pair ofinverted so-called Fresnel lenses 38 and 39 lying in the same gleneralplane, each of the Fresnel lenses in turn having a segment cut therefromand the two lenses 38 and 39 joined along their respective chords, i. e.along the line or chord 53 (Figure 2). As shown in Figure 1, lower lenssurfaces 41 and 5I join at a point 52 directly'below the point -42 whereupper convex surfaces 40 and 43 jon 40 and 43 which are wholly convexare adjacent y light source I2 and preferably center point 42 of lensl31 is positioned'in alignment with vthe center portion I2a of lightsource I2. This positioning of the lens not only facilitates cleaningthereof but also places the main body of the lens above the bottomhorizontal plane of lens portion 35 which considerably lessens theproduction of light streaks and glare therefrom and increases theintensity of the condensed light.

Referring now to Figure .4 wherein I show diagrammatically thedistributionof light from lens 31, it will be seen that light -rays Aemanating from source I2C. strike the upper convex surfaces 40 and 43 ofthe lens and are distorted by lens 31 so as to. emanate therefrom-Aintwo relatively distinct beams B and C which are suitably divergenttoyprovide spot illumination for a pair/of'seats; for example, when thelens is asymmetrically positioned thereover. Beams of light B and C thusamply illuminate the seats toward which they are directed but do A notcause glare outside of their locality. A sumcient diffusion of light,however, emanates from portions 34 and 35 (Figure 1) of the lens toprovide a soft illumination in the upper portion of thev car orenclosure in which the fixture is installed thus to dispell an otherwisegloomy atmosphere. Furthermore, this soft diffusion of light eliminatesto a considerable extent the glare which would otherwise be noticeablewhen the vision is directed straight at the lens as the brightness oflight emanationis graduated be-f. tween the brilliant part of lens I3,i. e. con-1 denser lens 31 and the relatively darker sur;-A roundingportions thereof, i. e. diffusing portion 35.

Referring now to Figure 5 in which I show my above-described lensmounted in a baggage rack support, the baggage rack includes asupporting arm 54 suitably secured to a side 55 of the car and extendingtherefrom to terminate in an upwardly curved portion 56. On oppositesides of arm 54 I provide substantially yvertical -side walls 51k (onlyone of which is shown) and these side walls with a. pair of partitions58 and 59 form an enclosure 60 in which the several parts of thelighting xture are disposed. An upper support 6I is pivotally connectedto the upper end of partition 58 by a hinge 62, support 6I beingprovided with downwardly projecting arms 63 and 64 and being held inrclosed position by a screw 16. Support arms 63 and 64 have securedthereto in any suitable manner a reector 65 which surrounds a lightsource 66 mounted in a socket 61 secured in any suitable manner topartition 58. Partition 58 has an opening 68 formed therein toaccommodate elec-v tric conductors 69 which are connected tol socket61.` It will appear that support 6I may be pivoted to the dotted lineposition to permit access to socket 61 and the lens therebelow.

An opening is formed on the bottom of supporting arm 54 through which alens generally indicated at 1I extends. Lensr1I is substantially similarto lens I3 (Figure 1) except that lens 1I is provided with a flange 12which rests upon a gasket 13 adjacent the edges of opening 10. Asuitable number of clips 14 are secured as by screws 16 to arm 54 andthese clips bear against lens flange 12`to hold the lens in its properoperative position.

As has been noted hereinabove, it is desirable to distribute lightuniformly over thel reading plane in the car, this reading plane beingapproximately 33 inches above the fioor of the car and at an angle ofabout 45 thereto. It is, however, quite difIicult to illuminate' thisreading plane uniformly when the light source is positionedasymmetrically with regard thereto. However, by utilizing myabove-described ler/is 1I (Figure 5) which throws the twin beams orspots B and C Y eicient manner.

As many possible embodiments may be made of 'thev above invention and asmany changes might be made in the embodiment above set forth, vit is tobe understood that all matter hereinbefor set forth, or shown in theaccompanying drawings, is to be interpreted as illustrative and not in alimiting sense.

I claim:

1. A lighting fixture for a railroad car or the like provided with aline of pairs of seats, said xture being asymmetrically disposed over apair of said seats and with respect to the reading planes relatedthereto, said ixture comprising, in combination, a reilector adapted tobe con-Y nected to the upper part of the car, a source of light adjacentsaid re'iiector, and a light-transmitting and diusing member adjacentsaid source of light and having a generally fiat bottom facing generallydownwardly of said car, a portion of said bottom being translucent andadapted to effect a general diffusion of light in the upper portion ofsaid car, the central portion of said member comprising a pair oi'CODCaVO-COIIVSX Condenser 1eI1SeSaCh arranged xture being asymmetricallydisposed over a pair of said seats and with respect to the readingplanes related thereto, said fixture comprising, in combination, areilector adapted to be connected to the upper part of the car, a sourceof light adjacent said reflector, and a light-transmitting and diiusingmember adjacent said source of light and having a generally iiat bottomfacing generally downwardly of said car, a portion of said bottom beingtranslucent and adapted to effect a general diiusion of light in theupper portion of said car, the central portion of said member comprisinga pair of concavo-convex condenser lenses, each arranged to direct aspot beam of light of uniform intensity over one of said reading planes,the concave portions of said lenses extending upwardly from the plane ofsaid bottom wall, said bottom wall including a plurality of corrugationsor the like, and spring' source.

LINDSLEY SCHEPMOES.

